1 . Field of the Invention:
This invention relates to a lens structure for a combined vehicle radio/audio tape cassette player or the like which includes a clear lens surrounded by an opaque field.
2. Description of the Prior Art
Lens structures of the type to which the present invention appertains are in common use for vehicle radios and audio tape cassette players. The lens structure is a plate-like element and includes a clear lens portion surrounded by an opaque field. The lens portion is for the display of information generated by the electronic equipment. This information may include, for example, the station to which the radio is tuned, whether the radio is set for AM or FM, whether the tape mode has been selected and the time of day.
In the past, such lens structures have been manufactured by first molding or otherwise preparing a clear plate of a scratch resistant glassy plastic material such as an acrylic resin. The rearward surface of this plate was then painted an opaque color, usually black, leaving a central clear lens area for the display of information.
This method of fabricating the lens structure has certain drawbacks. Firstly, the painted surface is easily scratched, thus necessitating very careful handling of the lens structure from the time it is painted to the time when it is installed. This results in costly procedures which are, however, not entirely effective, there being a relatively high scrap rate of such lens structures as a result of inadvertent scratching of the painted surface.
Additionally, it is difficult to properly paint such lens structures. In the painting process, a mask must be used to prevent painting the portion which is to remain clear. The mask gets paint on it and must be cleaned often to prevent making paint marks on the clear portion. Overall, this painting process also involves a relatively high scrap rate.
In accordance with the present invention, instead of painting the rear surface of the lens structure, a layer of opaque pigmented plastic material is heat molded onto the rear surface of the glassy panel. A clear lens portion projects through this opaque layer forming the desired lens.
Such a lens structure offers the advantage of ready quality control, there being no liquid paint to contend with. Additionally, the opaque layer, being pigmented and relatively thick, is not subject to easy scratching thereby resulting in a lower scrap rate and less expensive handling procedures. A further advantage of this construction is that a cheaper plastic can be used for the opaque layer than is used for the clear glassy layer.
Additionally, the lens structure permits a more efficient assembly process. In the past, because of the delicate nature of the lens structure, it has been mounted as a single unit to avoid damage to the painted surface. Such lens structures have an opening for insertion of a tape cassette. This opening is covered by a pivotally mounted door which is spring urged to the closed position. In the past, the assembly comprising the door, hinge pin and spring has been heat staked to the escutcheon of the cassette player with the lens structure then being separately mounted. In accordance with the present invention the lens structure and door assembly are first preassembled into a component which is then mounted as a unit thereby improving assembly efficiency. This is made possible by the fact that the lens structure can endure the preassembly handling without being damaged.